Abstract
The Demographic Buffering Hypothesis (DBH) predicts that natural
selection reduces the temporal fluctuations in demographic processes
(such as survival, development, and reproduction), due to their negative
impacts on population dynamics. However, a comprehensive approach that
allows for the examination of demographic buffering patterns across
multiple species is still lacking. Here, we propose a three-step
framework aimed at identifying and quantifying demographic buffering.
Firstly, we categorize species along a continuum of variance based on
their stochastic elasticities. Secondly, we examine the linear selection
gradients, followed by the examination of nonlinear selection gradients
as the third step. With these three steps, our framework overcomes
existing limitations of conventional approaches to identify and quantify
demographic buffering, allows for multi-species comparisons, and offers
insight into the evolutionary forces that shape demographic buffering.
We apply this framework to mammal species and discuss both the
advantages and potential of our framework.